MAC Address Learning Basics
In these videos, David Bombal demonstrates how MAC address tables are populated on network switches and how disabling MAC address learning causes traffic flooding.
CLIC Québec – L’heure du déclic pour la découverte et l’accès en ligne au contenu culturel québécois
Dans un contexte de renouvellement des politiques culturelles du Québec et du Canada à l’ère du numérique, ISOC Québec a lancé le projet « CLIC Québec » grâce à la subvention Beyond The Net octroyée par l’Internet Society en juillet 2017. Ainsi, depuis bientôt un an, ISOC Québec oeuvre à travers « CLIC Québec » d’une part à sensibiliser les décideurs politiques et les utilisateurs finaux et d’autre part à identifier et valoriser les bonnes pratiques des milieux culturels en matière de diffusion, de promotion et d’accès en ligne aux contenus et produits culturels locaux.
Profitant de la tenue du 1er Forum sur la Gouvernance d’Internet au Québec (FGI Québec), qui coïncidait avec les célébrations des 25 ans de l’Internet Society en septembre 2017, ISOC Québec a organisé un atelier intitulé Cultures en réseaux et découvrabilité des contenus locaux au cours duquel une soixantaine de participants (professionnels de la culture, experts et consultants en politiques culturelles, spécialistes des métadonnées et du Web sémantique, chercheurs/universitaires, citoyens et utilisateurs finaux) ont identifié ensemble dix pistes d’action susceptibles d’accroître la présence et le rayonnement des contenus culturels québécois sur Internet.
Pour mobiliser davantage les acteurs des différents secteurs des industries culturelles québécoises Continue reading
Avoid Summarization in Leaf-and-Spine Fabrics
I got this design improvement suggestion after publishing When Is BGP No Better than OSPF blog post:
Putting all the leafs in the same ASN and filtering routes sent down to the leafs (sending just a default) are potential enhancements that make BGP a nice option.
Tony Przygienda quickly wrote a one-line rebuttal: “unless links break ;-)”
Read more ...Ansible Tips and Tricks
A collection of useful Ansible tips and tricks.Ansible Tips and Tricks
A collection of useful tips and tricks for Ansible which don't really justify a full blog post on their own. I'll keep updating this post when I come across something of value. Callbacks Convert the output of a playbook run to json. Either set the stdout_callback = json setting in...Switch stacking for campus design: There’s a better way
We often receive the following campus design question: “do you support switch stacking?” This is a fair question, as many of the legacy vendors have promoted stacking designs for the past decade. It’s popular enough that people ask for it, so we must support it, right?
Well, the popular option isn’t always the best one, and switch stacking designs are a very good example of that philosophy. So when people ask if we support stacking, we think to ourselves “heck, no” before politely telling them that we do not because better options exist.
“Perfection is attained, not when there is nothing more to add, but when there is nothing more to take away.”
At Cumulus Networks, we believe that simplicity is the corner-stone of network design.
Or, to say it another way, complex designs fail in complex ways (shoutout to Eric Pulvino for that quote!). Our former Chief Scientist, Dinesh Dutt, gave an excellent explanation around the importance of simple building blocks in his Tech Field Day 9 Presentation (6min 50 seconds in).
Let’s address a little history on switch stacking and then break down the major technical downfalls of a stacking design, the stacking protocol itself, Continue reading
Cisco IOSXRv Vagrant Libvirt Box Install
Build a Cisco IOSXRv Vagrant box for use with the libvirt provider.Cisco IOSXRv Vagrant Libvirt Box Install
In this post I will cover how to create a Cisco IOSXRv Vagrant box for use with the vagrant-libvirt provider as well as enabling the netconf API. This post assumes a working installation of Vagrant with the vagrant-libvirt plugin already installed. You can follow this post to get the...Boston, London, & NY developers: We can’t wait to meet you
Photo by Patrick Tomasso / Unsplash
Are you based in Boston, London, or New York? There's a lot going on this month from the London Internet Summit to Developer Week New York and additional meetups in Boston and New York. Drop by our events and connect with the Cloudflare community.
Event #1 (Boston): UX, Integrations, & Developer Experience: A Panel feat. Drift & Cloudflare
Photo by The Opte Project / Originally from the English Wikipedia; description page is/was here.]
Tuesday, June 12: 6:00 pm - 8:00 pm
Location: Drift - 222 Berkley St, 6th Floor Boston, MA 02116
Join us at Drift HQ for a panel discussion on user experience, developer experience, and integration, featuring Elias Torres from Drift and Connor Peshek and Ollie Hsieh from Cloudflare.
The panelists will speak about their experiences developing user-facing applications, best practices they learned in the process, the integration of the Drift app and the Cloudflare Apps platform, and future platform features.
View Event Details & Register Here »
Event #2 (London): Cloudflare Internet Summit
Photo by Luca Micheli / Unsplash
Thursday, June 14: 9:00 am - 6:00 pm
Location: The Tobacco Dock - Wapping Ln, Continue reading
At Cisco Live!
The Network Collective crew—Jordan, Eyvonne, and I—will be at Cisco Live this week. You can normally find me hanging around the certifications or social media lounge, or just walking around the floor talking to folks. I’m presenting at the CCDE techtorial on Sunday.
Myth Busted: Who Says Software Based Networking Performance Does Not Match Physical Networking?
100 Gbps Performance with NSX Data Center
NSX Data Center has shown for some time now (see VMworld 2016 NSX Performane Session (NET 8030) that it can drive upwards of 100G of throughput per node for typical data center workloads. In that VMworld session, we ran a live demo showing the throughput being limited by the actual physical ports on the host, which were 2 x 40 Gbps, and not by NSX Data Center.
Typically, in physical networking, performance is measured in raw packets per seconds to assure variety of traffic at variable packet sizes be forwarded between multiple physical ports. While in virtualized data center this is not a case, as hypervisor hosts only have to satisfy few uplinks, typically no more than four physical links. In addition, most of the virtualized workload use TCP protocol. In that case. ESXi hypervisor fowards the TCP data segments in highly optimized way, thus not always based on number of packets transferred but the amount of data segment forwarded in software. In typical data center workloads, TCP optimizations such as TSO, LRO and RSS or Rx/Tx Filters help drive sufficient throughput at hardly any CPU cost. TSO/LRO help move large amounts of Continue reading
SevOne Supports Move From MPLS to SD-WAN With New Monitoring Tool
The initial release of the SevOne SD-WAN Monitoring software will give insights into Cisco-Viptela SD-WAN environments, but it will soon be extended to support other SD-WAN vendors.
Check Out Our New Network Programmability Course
Course Title: The Full Stack Engineer’s Guide to Network Programmability with Python
Course Duration: 30 hrs 33 min
The Full Stack Engineer’s Guide to Network Programmability with Python will provide learners with an inductive and comprehensive introduction to the Python programming language to include the various data types, control flow structures, functions, methods, classes, objects, reading and writing files, data storage using MySQL, and regular expressions. We will also cover on- and off-box Python automation and explore the guest shell in IOS-XE!
Data Center Server Buyers Choose White Box Over Dell EMC, IHS Says
White box beat Dell EMC in terms of data center server revenue and units shipped in the first quarter of 2018.
Linux Foundation Acknowledges Concerns About Microsoft’s Purchase of GitHub
The Linux Foundation Executive Director Jim Zemlin acknowledges that there are “still small pockets of deep mistrust of Microsoft in the open source community.”
Vodafone Optical Trials With Ciena Hit 400 Gb/s Over a Single Wavelength
One trial used the OIF's FlexEthernet client interface standard, the other was based on Ciena's WaveLogic Ai platform.
BT Axes Top Exec Gavin Patterson
The BT executive just last month announced plans to slash 13,000 jobs as part of a broader corporate restructuring. Investors were not happy.